JPS5938454B2 - Bearing device with an alignment bearing that prevents axial movement of the rotating shaft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an aligning bearing for supporting a rotating shaft of a rotating machine in a manner that allows limited angular excursion in a plane containing the axis but prevents axial movement relative to the stator. The present invention relates to a bearing device having the present invention.

The invention is particularly advantageously applicable to rotary machines having vertical axes and rotors of considerable weight and large diameter. Conventionally, in this type of bearing device, in order to define a spherical sliding region that allows angular deviation within a limited range of the rotating shaft, as shown in FIG. each substantially abuts a complementary portion of the surface of the bearing housing, which portions are usually convex and concentric spherical regions.

As explained below, such prior art required spherical bearings of considerable size and weight if the bearings were to support large loads. Furthermore, in order to maintain the rotating shaft in an accurate axial position,
Spherical bearings had to be designed with extremely small running clearances. However, if the movement gap is made small, there is an unavoidable risk that the bearing will become jammed or stuck, which may impede smooth sliding of the bearing. The present invention overcomes these problems in the prior art and provides a bearing device that is particularly applicable to rotating machines having a vertical axis and a heavy machine and has a small overall size. , which ensures that the axis of rotation is aligned and centered without any risk of vibration, irrespective of which direction the axial, linear thrust of the axis of rotation is directed.

In order to reduce the size of the bearing device and to prevent the aforementioned bearing from binding or sticking, one of the two spherical sliding regions is made freely movable relative to the rotation axis, It was investigated whether it was possible to bring the two spherical sliding regions closer to each other.

That is, in FIG. 1, if the two spherical sliding regions are brought closer to each other, the overall height C can naturally be reduced. What is necessary for this is that the centers of the two spherical sliding areas do not coincide, and that the center of one of the two spherical sliding areas is located outside the other sliding area, and The center of the other is located outside the sliding area of one (
In the embodiment shown in FIG. 2, which will be described later, the center of Z1 is set to 0 on the outside of Z2.
1, and the center of Z2 is outside Z1)
It is to do so. Such a configuration is only appropriate if certain operating conditions are met. Thus, in one embodiment of the bearing device according to the invention, at least one part of the spherical sliding area is concave and a part of the complementary shaped surface of the bearing housing is convex. A preferred embodiment is such that the other part of the spherical sliding area is convex and the part of the complementary shaped surface of the shaft housing is concave. Other features and advantages of the invention will become apparent from the following description of a bearing arrangement according to the invention embodying the characteristics outlined above in comparison with known bearing arrangements with reference to the drawings.

In order to analyze the drawbacks of conventional bearing arrangements in which the two spherical sliding regions are part of the same sphere (ie, have the same center), reference is first made to FIG.

FIG. 1 is a longitudinal sectional view of a conventional bearing device. The spherical bearing support member 11, which can swing within the bearing housing 12, has two
The shaft 13 is supported by two symmetrical inclined roller bearings 14.

The inner ring 141 of the bearing 14 is fitted onto the shaft 13 .
The ring 141 connects to the fixed annular flange 131 of the shaft 13;
one annular flange and a threaded portion 133 of the shaft 13;
The nut 132 is screwed into place and tightened into place. The spherical bearing support member 11, which is bored to accept the outer bearing ring 142, has an inner collar 1.
11 is held in place between outer bearing rings 142. Neglecting the average gap J, the sliding movement between the bearing housing 12 and the spherical bearing support 11 takes place via a spherical region with radius r whose center lies on the axis of the shaft 13. The sliding area is divided into two spherical areas Zl by an annular passage 15.
The passage 15 is defined by an annular groove 121 formed in the bearing housing 12 and a portion 112 formed on the circumferential surface of the spherical bearing support member 11 by cutting. This passage 15 ensures lubrication of the spherical bearing support member. This guide device allows the shaft 13 to be approximately angularly displaced about the center 0, while ensuring a precise axial positioning of the shaft 13.

However, if the overall height h is reduced without changing the radius of the sliding region, the thrust angle a will decrease, and there is a risk that it will eventually stop moving when the axial load becomes large. Moreover, the gap j between the spherical bearing support member and its housing needs to be reduced in order to limit the axial play, but then there is a risk that it will become stuck at some point during operation and , machining is difficult during manufacturing. In order to overcome these drawbacks,
Under a constant gap j, in order to increase the thrust angle a and reduce the axial play, it is conceivable to increase the height C so that it covers the bearing support member at the apex of the spherical sliding area. In this case, when the load in the axial direction increases, the bearing device becomes extremely large and heavy compared to the shaft diameter. Before describing one embodiment of the bearing device according to the present invention with reference to FIG. 8, let us explain the self-aligning thrust bearing provided in the bearing device of the present invention, which can overcome the drawbacks of the conventional bearing device shown in FIG. This will be considered with reference to FIGS. 2 to 7.

As shown in all these figures, the feature that overcomes the drawbacks of the prior art lies in the creation of two spherical sliding regions Zl, Z2 that differ even in their centers and radii. This causes the vertices of both regions to be significantly closer to each other than if the sliding regions were formed of the same spherical surface. The angular deviation of the axis is
In order to make this possible without allowing excessive gaps, it is generally found necessary to provide a certain degree of freedom of lateral deviation to the spherical center of one of the two sliding regions (Z2 in the figure). For this purpose, the surface part of the spherical bearing housing that engages with the sliding area is constituted by a so-called "floating" ring, which rests against the housing body in a manner that allows free lateral sliding. The thrust bearings shown in FIGS. 2 to 7, which are shown in operating positions, are intended to guide the rotor of a rotating machine having a vertical axis, the center of gravity of which is designated by G.

The rotor is assumed to be located above the thrust bearing. Reference numeral 01 indicates a fixing point which is the spherical center of the spherical sliding region Z1 formed in the bearing support member. The center of the "floating" spherical sliding region Z2 is not shown. In FIG. 2, a spherical bearing support member 21 defining sliding areas Zl, Z2
Both parts are convex.

A floating ring 23, which cooperates with the spherical bearing support 21 by means of a sliding region Z2, is placed above the spherical bearing support 21. Area Z1 is located below and has a center 0 close to the center of gravity G.
1 is located above. In the rest position, the spherical bearing support member 21, which is pressed downwardly by the weight of the rotor, is properly centered with respect to the bearing housing 22 by the area Z1. However, during machine operation, if the spherical bearing support member 21 is pushed upward by the reaction of the rotor and the area Z
If the spherical bearing support member 21 is received in the floating ring 23 by 2, centering or alignment is no longer guaranteed. FIG. 3 shows another solution using a biconvex spherical bearing support member.

When the machine is stopped, the spherical bearing support member 31 rests on a floating ring 33 against the bottom of the bearing housing 32. Region Z1 is located to ensure accurate alignment of the spherical bearing support member by the upward thrust of the rotor during operation. It is not so much a problem that the center is not aligned in the rest position. On the other hand, a consideration of FIGS. 4 and 5 shows that concave and convex spherical thrust bearing support members can ensure center alignment under all operating conditions. In FIG. 4, the spherical bearing support member 4
The convex surface of 1 rests against a fixed part of the housing 42 (fixed spherical sliding area Z1) in the rest position.

The concave surface of the bearing support member 41 in combination with the floating ring 43 defines a floating spherical sliding area Z2. The fixed center 01 is extremely close to the center of gravity G. In-operation alignment, as in the case of the biconvex spherical bearing of FIG. 2, is accurate only if the rotor reaction in operation occurs in a downward direction, i.e. in the same direction as the thrust at rest. However, if this reaction occurs in an upward direction, it is necessary to place a floating ring 53 beneath the spherical bearing support member 51 by shaping it to fit the convex surface of the bearing support member 51, as shown in FIG. When the thrust is assumed to be upward, the top concave surface of the spherical bearing support member 51 contacts a complementary shaped portion of the fixed portion of the housing 52 . Alignment is not ensured in a stationary state, but this is okay. On the other hand,
During operation, the alignment force is applied dynamically. It should be noted that the suspension distance between G(!:01) in the two cases of FIGS. 4 and 5 can be made extremely small by adjusting the radius of the spherical sliding region Z1. Since the center of gravity G is always on the rotation axis, there are many spherical sliding regions near G.
The fact that there is a spherical center 01 means that the center of this spherical sliding region Z1 does not deviate from the axis too much.

Thus, reducing the suspension distance between G (501) ensures accurate alignment of the bearing regardless of the direction of thrust during operation.Finally, the present invention is shown in FIG. , a biconcave spherical bearing support member as shown in FIG. 7 can be constructed.

In FIG. 6, the bearing support member 61 has two concave spherical sliding areas. The bearing support material abuts the floating ring 63 at the bottom position and a complementary shaped part of the bearing housing 62 at the top position. In FIG. 7, the spherical bearing support member 71 is also biconcave, but the floating ring 7
3 is placed above, while the spherical bearing support member 71 abuts a complementary shaped part of the bearing housing 72 in the bottom position. It is clear from the positions of points G and 01 in these two drawings that only the construction system shown in FIG. To obtain a rotor with a vertical axis, however, if the center of gravity G is located above the spherical bearing support, the thrust exerted by the rotor during operation is directed upwards. Thus, it can be said in general that a biconvex spherical bearing support member (as shown in Figure 2) will only achieve accurate alignment when the thrust is directed towards the spherical bearing support member from the center of gravity. It is possible, in which case the floating ring is placed against the sliding area surface of the spherical bearing support member closest to said center of gravity, whereas a biconcave spherical bearing support member has a thrust force that is that it is possible to obtain a precise alignment when facing from the bearing support member towards the center of gravity, in which case the floating ring is placed against the sliding area surface of the spherical bearing support member remote from said center of gravity; It is.
A biconcave spherical bearing support member may therefore be employed in place of a concavo-convex bearing support member (as shown in FIG. 4) if operating conditions permit this.

Because of their symmetry, biconcave bearing supports have the advantage that they can be machined more easily and economically, and the fact that the housing encloses two concave spherical areas reduces the total axial length, i.e. The overall height can be made smaller. FIG. 8 shows an embodiment of a bearing arrangement with a concave-convex self-aligning thrust bearing according to the invention, a so-called alignment bearing, for a rotating machine with a vertical axis, the rotor center of gravity G being located above said thrust bearing. However, the mouth of the rotating machine is intended to produce an upward thrust during operation.

FIG. 8 shows a modification of the one shown in FIG. 4.
The free coupling of rotational movement between the spherical bearing support member 81 and the rotating shaft 83 is ensured by a guide bearing 811 of the fluid film lift type as described in French Patent No. 2,147,398. As explained in this patent, the bearing includes a movable bearing bushing that is pushed back onto the shaft by a spring-loaded pusher to operate under optimal hydrodynamic conditions. The guide bearing 811 is fitted into an annular chamber formed in the inner cavity of the spherical bearing support member 81, which is also inserted between the annular flanges 831, 832 of the shaft 83. For ease of assembly, the spherical bearing support member 81 can be divided into two halves with an axial seam. The part of the spherical bearing support member defining the fixed spherical sliding area Z2, which communicates with a corresponding part of the surface of the housing 82, is concave, and the other part of the spherical bearing support member defining a floating spherical sliding area Z2. forms a convex surface. this is,
This results in a significantly smaller height h and an even more significant increase in the thrust angle a determined by the selection of radii 1 and r2. In the bearing device according to the present invention, the height of the bearing is small, the distance between the receiving images of the spherical bearing support member 81 that abuts the annular flanges 831 and 832 is small, and the spherical bearing support member has unevenness. The hydrodynamic guide bearings shown in the French patent, whether shaped or biconcave, can be used to advantage.

If a bearing 14 such as that used in the conventional guide device shown in FIG. 1 is used, the annular flanges 831, 832
(Otherwise, the distance between the bearing surfaces of the bearing support member that comes into contact with the
In this case, one of the objects of the present invention, which is to reduce the height h, cannot be achieved (therefore, it is preferable to use a bearing as shown in the above-mentioned French patent). be). In FIG. 8, between the annular flanges 831, 832 and the receiving surfaces indicated at 833 and 834, an anti-friction member, that is, a self-lubricating suitable alloy layer provided on the receiving surfaces is interposed. .

The spherical bearing housing 82 includes a casing 8 with a flat bottom wall on which a floating ring 822 is slidably mounted.
21, the floating ring 822 is adapted to cooperate with the convex surface of the spherical bearing support member 81 so as to constitute a floating spherical sliding region Z2.

The casing 821 is closed by a lid 823, and the lid 823 is formed with an annular boss that communicates with the concave surface of the spherical bearing support member 81 so as to define a sliding region Z1. During operation of the machine, the fluctuations and inclinations of the movement gap in the area Z2 that appear when the shaft 83 is subjected to small angle deviations are (area Z
1 in contact) has a very low value with very little geometrical error relative to the design clearance, so that the operation of the bearing arrangement is not affected.

The radii Rl, r2 of the spherical sliding regions Zl, Z2 are shown to be equal in FIG. However, there is no harm in selecting unequal radii if this is required due to construction or service stress. As previously stated, many structural variations are possible without departing from the scope of the invention.

In particular, the invention can be applied in any case where a bearing arrangement with self-aligning bearings is required but only limited space is available. Furthermore, the bearing arrangement according to the invention may include any known type of guide bearing, but as already mentioned, the use of a hydrodynamic guide bearing of the type described with respect to FIG. It is particularly advantageous for small reasons.

[Brief explanation of drawings]

1 is a longitudinal sectional view of a bearing arrangement with a self-aligning thrust bearing of a known type; FIGS. 2 and 3 are diagrams of a self-aligning thrust bearing with two convex, non-concentric sliding surfaces; FIG. 4, 5, 6 and 7 are diagrammatic sectional views of a self-aligning thrust bearing in which at least one portion of the spherical surface is concave; FIG. 1 shows a longitudinal section through an embodiment of a bearing arrangement with an aligned thrust bearing; FIG. Unless otherwise necessary for explanation, these drawings include: For example, lubricating devices and lubrication pipes, detailed arrangements and plan views of guide devices for assembly and disassembly, assembly elements and other elements or devices not necessarily required for a clearer understanding of the invention are not shown. Reference numerals Zl and Z2 represent "spherical sliding regions," reference numeral 822 represents a "ring," and reference numeral 83 represents a "rotation axis."

Claims (1)

[Scope of Claims] 1. The rotating machine has an alignment bearing that supports the rotating shaft of the rotating machine in a manner that allows limited angular deviation in a plane including the axis but prevents movement in the axial direction relative to the stator; A bearing device having a spherical bearing support member movable in a housing provided in a stator, the bearing support member having two spherical sliding regions, each of which has a different center. forming part of a sphere, one of the regions adapted to cooperate with a complementary surface formed on a ring, and the other of said regions facing the complementary surface of said ring; The ring is adapted to cooperate with a complementary surface formed on a surface of the housing, and the ring is movable within the housing in a direction transverse to the axis of the axis of rotation. bearing device. 2. Bearing arrangement according to claim 1, characterized in that the two spherical sliding regions are both convex and cooperate with complementary concave surfaces of the housing. 3. One of the two spherical sliding regions is convex and cooperates with a complementary concave surface of the housing, and the other sliding region is concave and cooperates with a complementary convex surface of the housing. A bearing device according to claim 1, characterized in that: 4. Bearing arrangement according to claim 1, characterized in that the two spherical sliding areas are both concave and cooperate with complementary convex surfaces of the housing.